Electric projection lamp



March 10, 1936. T. w. FRECH ELECTRIC PROJECTION LAMP Filed June 9, 1953[NI/ENTER. T212701 0A5 WFREZH .575 AT TURKEY" Patented Mar. 10, 1936UNITED STATES PATENT OFFICE ELECTRIC PROJECTION LAMP ration of New YorkApplication June 9, 1933, Serial No. 675,025

14 Claims.

My invention relates to electric lamps and mountings therefor, and isespecially adaptable and useful in cases where the light source shouldoccupy a definite position with reference to some associated part orstructure, such as a. reflector or a lens. The invention is ofparticular advantage for projection lamps such as vehicle headlamps, inwhich an incandescentfilament lamp is mounted in a reflector such as thewell-known paraboloid reflector.

In headlamps as at present constructed, the lamp is mounted by insertingits cylindrical base bearing bayonet pins in a tubular socket havingbayonet slots which is itself mounted in an opening at the apex of thereflector, with suitable provisions for adjusting the socket relative tothe reflector to "focus" the light source of the lamp to exactly theright position for any desired distribution of light. While thisarrangement permits easy removal and replacement of a lamp as well asaccurate focusing, yet it is mechanically complicated, and often liableto derangements which allow the lamp to shift out of focus.

To overcome these disadvantages of present practice I prefer to securethe lamp base directly to the reflector instead of securing the lampbase to a socket and afterwards obtaining the proper adjustment bymovement of the socket. This is done in such a way that when a givenlamp is oncesecured to a reflector, it is permanently and accuratelylocated and further adjustment is unnecessary. The particular lamp canstill be removed and replaced as often as desired,--for cleaning of thelamp or its reflector, etc.

For removably mounting the lamp, its base is provided with means adaptedto engage in a perfectly definite and fixed relation with an accuratelylocated and fixed part or engagement means of the reflector, provisionbeing also made for holding said base and reflector engagement means inproper engagement, preferably by spring pressure. This requires, ofcourse, that the engagement means on the base be properly adjusted andfixed relatively to the light source; and while this may be accomplishedby extreme accuracy in the basing of the lamp, yet I prefer to embodythe engagement means of the base in a separate part'or adapter that canbe properly adjusted on the base and permanently fixed thereto,-as bysoldering, or other methods of forming a fused joint. For bringing thesecuring means of base and reflector into proper relation to be heldengaged by spring pressure, axial and rotary movement of the lamprelatively to the reflector is preferred. Further features andadvantages of my invention will appear from the following description ofspecies thereof, and from the drawing.

In the drawing, Fig. l is an elevation, in section, of a headlampconstructed according to my invention; andFig. 2 is a disassembledperspective view of the various parts thereof; Fig. 3 is a partialvertical section on an enlarged scale of the assembly shown in Fig. l.

. Referring to the drawing, the lamp com- 1( prises a bulb I i having afilament l2 sealed therein and mounted on leading-in wires B. A base Hcomprising a tubular shell i5 is mounted on said bulb I I and carries aterminal pin l6 mounted in insulating material I! and protruding beyondthe end of said base. One of the leading-in wires I3 is connected to thepin l6 and the other is connected to the shell 15. An adapter I8 comprising a narrow band or shell 19 having a transversely extendingprojection or flange 20 at one 2 end thereof is mounted on the baseshell I5. The adapter [8 is located on the base ll so that the flange 20(or the back surface thereof), bears a definite relation to the filamentII, the shell [9 of said adapter being of slightly larger diameter thanthe shell l5 so that the lamp base may be rockedand shifted therein tolocate the filament along the axis of the flange and transverselythereto. The band IQ of the adapter may of course be omitted and theflange 20 used alone so as a ring, or the said flange may beincorporated in the base shell l5 itself. A plurality of lugs or wingsmay also be substituted for the continuous flange 20. A plurality ofopenings preferably bayonet slots 2i (three being illustrated) are 3:formed in the flange 20 and are preferably unequally spaced. Each ofsaid slots 2! comprises an enlarged circular portion 22 at one endadapted to slip over the head 23 of a cooperating pin 24 resilientlymounted on the reflector 25, and a a smaller circular portion 26 at theother end adapted to engage a portion of the head of said pin 24. Thesaid slots 2| may be termed arcuate in the sense that they permit arotary movement of the lamp during the mounting operation and 4. bayonetin the sense that they cooperate with the pins 24 in the mounting andpositioning of the lamp. It will be obvious that the afore-describedconstruction provides openings, which allow the flange to clear the pinheads, and cam edges on the 5- flange which, after the portions 22having the greatest clearance are slipped over the heads of the pins 24and the lamp rotated, cause the said pins to be first advanced and thenallow them to be retracted by the spring 3| to settle in the seat- 5 ingportions 26 each of which has a. predetermined angular relation to thefilament.

The reflector comprises a flattened or plane portion 21 at the apexthereof having an opening 28 therein to permit insertion of the lampbase It, the front or inner surface of said flattened portion 2! bearinga definite relation to the focal point. The pins 24 are mounted in holes29 at the margin of hole 28 in the flattened portion 2! of the reflectorand extend through holes in a ring-shaped spring member 3|, beingresiliently held against the reflector thereby. The rear ends'32 of thepins 24 are pinched and flattened to hold the spring member 3| in placethrough the intervention of washers 33., The ring-shaped spring member3| has a plurality of V-shaped indentations or protuberances 34 therein,preferably three, one being located between each of the holes 30. Thesaid indentations 34 bear against the back of the flattened portion 21of the reflector and thus impart a spring efiect to the intermediateportions of the ring 3| when the heads of the pins 24 are pulled forwardby the flange 20 of the lamp, as hereinafter explained. The springmember 3| may, of course, take other shapes or forms, or each of thepins 24 may carry a separate spring, such as a helical wire spring.

To mount the lamp Ill, the base i4 is inserted in the opening 28 of thereflector until flange 20 engages the flattened portion 21 of thereflector, the circular portions 22 of slots 2I-belng slipped over theheads 23 of pins'24. The back surfaces -of the heads 23 of pins 24are'made conical in shape so that when the lamp ill isxnow rotatedclockwise, the said surfaces 35 will ride up on the narrowing portionsof slots 2|, through the restricted portions 36, and settle into thecircular portions 26, being held firmly therein by the spring member 3|.It will be obvious that the angular positions of the portions 26predetermine the angular position of the filament |2. It will beobvious, also, that the use of unequally spaced slots to correspond withthe unequally spaced retaining pins, hereinbefore referred to, insuresthe proper insertion of the lamp.

It is apparent from the drawing that this construction provides a verycompact, sturdy "and eflicient means of accurately mounting a lamp.

Electrical connection is made to the terminal pin 6 by any suitablemeans, such as a connector comprising a helical coil of wire adapted tobe slipped over said pin and having a number of turns offset so as toprovide a firm contact with said pin. Such a connector is disclosed inU. S. patent application, Serial No. 663,357, Geiger, filed March 29,1933.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:--

1. Thecombination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending projection accuratelylocated with respect to said light source, and a reflector having aspring actuated pin mounted thereon, said lamp projection having anarcuate slot therein for engaging said pin to lock said lamp againstsaid reflector upon arotary movement of said lamp.

2. The combination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending flange accu-- ratelylocated with respect to said light source, and a reflector having aspring actuated pin mounted thereon, said lamp flange having an arcuateslot therein for engaging said pin to lock said lamp against saidreflector upon a rotary movement of said lamp.

3. The combination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending flange accurate lylocated with respect to said light source, and a. reflector having aplurality of spring actuated pins mounted thereon, said lamp flangehaving a plurality of arcuate slots therein for engaging said pins tolock said lamp against said reflector upon a rotary movement of saidlamp.

4. The combination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending projection accuratelylocated with respect to said light source, a reflector having a pinmounted thereon, and spring means mounted on said reflector and engagingsaid pin, said lamp projection having an arcuate slot therein forengaging said pin to lock said lamp against said reflector upon a rotarymovement of said lamp.

5. The combination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending projection accuratelylocated with respectto' said light source, a reflector having a pinmounted thereon, and spring means mounted on said reflector and engagingsaid pin, said pin comprising a head the back of which is conical inshape, and said lamp projection having a slot therein for' engaging saidconical portion of said pin head to lock said iamp in said reflector.

, a reflector having a pin mounted thereon, and

spring means mounted on said reflector and engaging said pin, said pincomprising a head portion located at the inside of said reflector, theback of said pin head being conical in shape, and said lamp projectionhaving an elongated slot therein adapted to slip over said pin head andallow rotation of said lamp until said conical portion of said pin headseats in a portion of said slot to lock said lamp in said reflector.

7. The combination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending flange accuratelylocated with respect to said light source and having a plurality ofarcuate cam engagement surfaces therein, and a reflector having a lampbase opening therein and a plurality of spring actuated pins disposedaround the margin of said lamp base opening and having head portions thebacks of which engage said arcuate cam means in said lamp base flange topress said flange against said reflector upon a rotary movement of saidlamp.

8. The combination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending flange accuratelylocated with respect to said light source and hav- -ing a plurality ofarcuate slots therein, and a reflector having a lamp base openingtherein and a plurality of spring actuated pins disposed around themargin of said lamp base opening and having head portions the backs ofwhich engage said arcuate slots in said lamp base flange to press saidflange against said reflector upon a rotary movement of said lamp.

9. The combination of a lamp comprising a bulb having a light sourcetherein and a base having a transversely extending flange accuratelylocated with respect to said light source and having a plurality ofarcuate slots therein of varying width, and a reflector having a lampbase opening therein and a plurality of spring actuated pins disposedaround the margin of said lamp. base opening and having head portionsthe backs of which are conical in shape and engage said arcuate slots insaid lamp base flange to press said flange against said reflector upon arotary movement of said lamp.

10. In an electric lamp for light beam projecting devices, thecombination of a bulb, a base, a filament within said bulb, and atransversely extending flange accurately located on said base at apredetermined distance and in a predetermined plane with respect to saidfilament, and means for predetermining the angular position ofsaid-filament when said lamp is mounted including a plurality of spacedbayonet slots in said flange, corresponding end portions of which havepredetermined angular relations to said filament.

11. In an electric lamp for light beam projecting devices, thecombination of a bulb, a base, a filament within said bulb, and atransversely extending flange accurately located on said base at apredetermined distance and in a predetermined plane with respect to saidfilament and means for predetermining the angular position of saidfilament when said lamp is mounted including a plurality of spacedbayonet slots in said flange, corresponding end portions of which havepredetermined angular relations to said filament, each of said slotsbeing larger at one end than at the other with an intermediaterestricted portion.

12. In an electric lamp for light beam projecting devices, thecombination of a bulb, a base, a filament within said bulb. and atransversely extending flange accurately located on said base at apredetermined distance and in a predetermined plane with respect to saidfilament, and having a plurality of asymetrically spaced bayonet-slotstherein, corresponding end portions of which have predetermined angularrelations to said filament.

13. In an electric lamp for light beam projecting devices, thecombination of a bulb, a base, a filament within said bulb, and atransversely extending flange substantially entirely surrounding andaccurately located on said base at a predetermined distance and in apredetermined plane with respect to said filament, and means forpredetermining the angular position of said filament when said lamp ismounted including three spaced bayonet slots in said flange,corresponding end portions of which have predetermined angular relationsto said filament.

14. In an electric lamp for light beam projecting devices, thecombination of a bulb, a base, a filament within said bulb, and atransversely extending flange accurately located on said base at apredetermined distance and in a predetermined plane with respect to saidfilament, and means for predeterrhining the angular position of saidfilament when said lamp is mounted including a plurality of spacedopenings in said flange, said flange being provided with cam edgeshaving seating portions each of which has a predetermined angularrelation to said filament.

THEODORE W. FRECH.

DISCLAIMER 2,033,699.-17wodore W. Fresh, Shaker Heights, Ohio. ELECTRICPROJECTION LAMP. Patent dated March 10, 1936. Disclaimer filed April 10,1939, by the assignee, GeneralElectric Company. P Hereby enters thisdisclaimer to claims 10, 11, 12, 13, and 14 of said Letters atent.

[Ofiicial Gazette May 2, 1.939.]

